Session description protocol (SDP) is defined in Internet Engineering Task Force (IETF) request for comments (RFC) 4566; the disclosure of which is incorporated by reference herein in its entirety. SDP is usable for describing multimedia sessions for the purposes of session announcement, session invitation, and other forms of multimedia session initiation. SDP also provides a framework by which it can be extended easily as new multimedia services and capabilities are introduced. For example, for an audio service, if a new audio codec is defined, SDP can be extended to advertise the new codec parameters to the participants in the audio service.
A policy and charging rules function (PCRF) may use SDP information to derive policy and charging control (PCC) rules, such as quality of service (QOS) and charging characteristics, for different multimedia sessions. For example, a PCRF may take different actions based on different SDP parameters. In this example, if a media type advertised in an SDP message is audio as opposed to video, different amount of bandwidth may need to be reserved in the network. Even if the codec and the media type remain the same, but attributes of the codec changes (e.g., the octet-aligned parameter for the AMR-WB codec), the amount of bandwidth reserved in the network may also need to change.
As new multimedia services are introduced, new SDP parameters (e.g., as codecs, clock rates, attribute lines, packetization times, etc.) and/or SDP extensions may also be introduced. In order to support new SDP parameters and/or SDP extensions, a conventional PCRF needs software modifications to incorporate the new SDP parameters and/or SDP extensions. However, such modifications can be time consuming and error-prone which may be undesired to network operators or other users.
Accordingly, there exists a need for methods, systems, and computer readable media for using user defined SDP rules.